Duration of sexual abstinence: epididymal and accessory sex gland secretions and their relationship to sperm motility

BACKGROUND: The data on the association between the abstinence period and sperm motility are conflicting. METHODS: Ejaculates from 422 men assessed for infertility were analysed according to the World Health Organization (WHO) guidelines. Seminal plasma neutral alpha-glucosidase (NAG), prostate-specific antigen (PSA), zinc and fructose were measured. Three groups were defined according to the length of sexual abstinence: G(2-3) (2-3 days), G(4-5) (4-5 days) and G(6-7) (6-7 days). RESULTS: The total percentage of progressively motile spermatozoa was significantly higher in G(4-5) compared with G(2-3) and G(6-7) (medians 55 versus 47 and 42%: P = 0.039 and P < 0.001, respectively). The percentage of spermatozoa with tail defects was significantly higher in G(6-7) compared with G(2-3) and G(4-5) (medians 14 versus 10 and 10%; P = 0.011 and P = 0.002. respectively). NAG was significantly lower in G(2-3) compared with G(4-5) and G(6-7) (medians 23 versus 34 and 34mU/ejaculate; P < 0.001 and P = 0.001, respectively). The same trend was found regarding zinc (medians 6 versus 8 and 8 mumol/ejaculate; P = 0.001 and P = 0.005, respectively). CONCLUSIONS: Within the time interval recommended by the WHO (2-7 days), the length of the abstinence period is associated with sperm characteristics and should be taken into consideration when interpreting results of semen analysis.